1 /*- 2 * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 #include <sys/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 /* 30 * The FreeBSD IP packet firewall, main file 31 */ 32 33 #include "opt_ipfw.h" 34 #include "opt_ipdivert.h" 35 #include "opt_inet.h" 36 #ifndef INET 37 #error "IPFIREWALL requires INET" 38 #endif /* INET */ 39 #include "opt_inet6.h" 40 #include "opt_ipsec.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/condvar.h> 45 #include <sys/eventhandler.h> 46 #include <sys/malloc.h> 47 #include <sys/mbuf.h> 48 #include <sys/kernel.h> 49 #include <sys/lock.h> 50 #include <sys/jail.h> 51 #include <sys/module.h> 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/rwlock.h> 55 #include <sys/socket.h> 56 #include <sys/socketvar.h> 57 #include <sys/sysctl.h> 58 #include <sys/syslog.h> 59 #include <sys/ucred.h> 60 #include <net/ethernet.h> /* for ETHERTYPE_IP */ 61 #include <net/if.h> 62 #include <net/route.h> 63 #include <net/pf_mtag.h> 64 #include <net/pfil.h> 65 #include <net/vnet.h> 66 67 #include <netinet/in.h> 68 #include <netinet/in_var.h> 69 #include <netinet/in_pcb.h> 70 #include <netinet/ip.h> 71 #include <netinet/ip_var.h> 72 #include <netinet/ip_icmp.h> 73 #include <netinet/ip_fw.h> 74 #include <netinet/ip_carp.h> 75 #include <netinet/pim.h> 76 #include <netinet/tcp_var.h> 77 #include <netinet/udp.h> 78 #include <netinet/udp_var.h> 79 #include <netinet/sctp.h> 80 81 #include <netinet/ip6.h> 82 #include <netinet/icmp6.h> 83 #ifdef INET6 84 #include <netinet6/in6_pcb.h> 85 #include <netinet6/scope6_var.h> 86 #include <netinet6/ip6_var.h> 87 #endif 88 89 #include <netpfil/ipfw/ip_fw_private.h> 90 91 #include <machine/in_cksum.h> /* XXX for in_cksum */ 92 93 #ifdef MAC 94 #include <security/mac/mac_framework.h> 95 #endif 96 97 /* 98 * static variables followed by global ones. 99 * All ipfw global variables are here. 100 */ 101 102 /* ipfw_vnet_ready controls when we are open for business */ 103 static VNET_DEFINE(int, ipfw_vnet_ready) = 0; 104 #define V_ipfw_vnet_ready VNET(ipfw_vnet_ready) 105 106 static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 107 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 108 109 static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 110 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 111 112 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 113 static int default_to_accept = 1; 114 #else 115 static int default_to_accept; 116 #endif 117 118 VNET_DEFINE(int, autoinc_step); 119 VNET_DEFINE(int, fw_one_pass) = 1; 120 121 VNET_DEFINE(unsigned int, fw_tables_max); 122 /* Use 128 tables by default */ 123 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 124 125 /* 126 * Each rule belongs to one of 32 different sets (0..31). 127 * The variable set_disable contains one bit per set. 128 * If the bit is set, all rules in the corresponding set 129 * are disabled. Set RESVD_SET(31) is reserved for the default rule 130 * and rules that are not deleted by the flush command, 131 * and CANNOT be disabled. 132 * Rules in set RESVD_SET can only be deleted individually. 133 */ 134 VNET_DEFINE(u_int32_t, set_disable); 135 #define V_set_disable VNET(set_disable) 136 137 VNET_DEFINE(int, fw_verbose); 138 /* counter for ipfw_log(NULL...) */ 139 VNET_DEFINE(u_int64_t, norule_counter); 140 VNET_DEFINE(int, verbose_limit); 141 142 /* layer3_chain contains the list of rules for layer 3 */ 143 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 144 145 ipfw_nat_t *ipfw_nat_ptr = NULL; 146 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 147 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 148 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 149 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 150 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 151 152 #ifdef SYSCTL_NODE 153 uint32_t dummy_def = IPFW_DEFAULT_RULE; 154 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 155 156 SYSBEGIN(f3) 157 158 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 159 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 160 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 161 "Only do a single pass through ipfw when using dummynet(4)"); 162 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 163 CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 164 "Rule number auto-increment step"); 165 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose, 166 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 167 "Log matches to ipfw rules"); 168 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 169 CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 170 "Set upper limit of matches of ipfw rules logged"); 171 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 172 &dummy_def, 0, 173 "The default/max possible rule number."); 174 SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 175 CTLTYPE_UINT|CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 176 "Maximum number of tables"); 177 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 178 &default_to_accept, 0, 179 "Make the default rule accept all packets."); 180 TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept); 181 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 182 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count, 183 CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 184 "Number of static rules"); 185 186 #ifdef INET6 187 SYSCTL_DECL(_net_inet6_ip6); 188 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 189 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 190 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0, 191 "Deny packets with unknown IPv6 Extension Headers"); 192 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 193 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0, 194 "Permit single packet IPv6 fragments"); 195 #endif /* INET6 */ 196 197 SYSEND 198 199 #endif /* SYSCTL_NODE */ 200 201 202 /* 203 * Some macros used in the various matching options. 204 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 205 * Other macros just cast void * into the appropriate type 206 */ 207 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 208 #define TCP(p) ((struct tcphdr *)(p)) 209 #define SCTP(p) ((struct sctphdr *)(p)) 210 #define UDP(p) ((struct udphdr *)(p)) 211 #define ICMP(p) ((struct icmphdr *)(p)) 212 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 213 214 static __inline int 215 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 216 { 217 int type = icmp->icmp_type; 218 219 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 220 } 221 222 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 223 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 224 225 static int 226 is_icmp_query(struct icmphdr *icmp) 227 { 228 int type = icmp->icmp_type; 229 230 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 231 } 232 #undef TT 233 234 /* 235 * The following checks use two arrays of 8 or 16 bits to store the 236 * bits that we want set or clear, respectively. They are in the 237 * low and high half of cmd->arg1 or cmd->d[0]. 238 * 239 * We scan options and store the bits we find set. We succeed if 240 * 241 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 242 * 243 * The code is sometimes optimized not to store additional variables. 244 */ 245 246 static int 247 flags_match(ipfw_insn *cmd, u_int8_t bits) 248 { 249 u_char want_clear; 250 bits = ~bits; 251 252 if ( ((cmd->arg1 & 0xff) & bits) != 0) 253 return 0; /* some bits we want set were clear */ 254 want_clear = (cmd->arg1 >> 8) & 0xff; 255 if ( (want_clear & bits) != want_clear) 256 return 0; /* some bits we want clear were set */ 257 return 1; 258 } 259 260 static int 261 ipopts_match(struct ip *ip, ipfw_insn *cmd) 262 { 263 int optlen, bits = 0; 264 u_char *cp = (u_char *)(ip + 1); 265 int x = (ip->ip_hl << 2) - sizeof (struct ip); 266 267 for (; x > 0; x -= optlen, cp += optlen) { 268 int opt = cp[IPOPT_OPTVAL]; 269 270 if (opt == IPOPT_EOL) 271 break; 272 if (opt == IPOPT_NOP) 273 optlen = 1; 274 else { 275 optlen = cp[IPOPT_OLEN]; 276 if (optlen <= 0 || optlen > x) 277 return 0; /* invalid or truncated */ 278 } 279 switch (opt) { 280 281 default: 282 break; 283 284 case IPOPT_LSRR: 285 bits |= IP_FW_IPOPT_LSRR; 286 break; 287 288 case IPOPT_SSRR: 289 bits |= IP_FW_IPOPT_SSRR; 290 break; 291 292 case IPOPT_RR: 293 bits |= IP_FW_IPOPT_RR; 294 break; 295 296 case IPOPT_TS: 297 bits |= IP_FW_IPOPT_TS; 298 break; 299 } 300 } 301 return (flags_match(cmd, bits)); 302 } 303 304 static int 305 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 306 { 307 int optlen, bits = 0; 308 u_char *cp = (u_char *)(tcp + 1); 309 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 310 311 for (; x > 0; x -= optlen, cp += optlen) { 312 int opt = cp[0]; 313 if (opt == TCPOPT_EOL) 314 break; 315 if (opt == TCPOPT_NOP) 316 optlen = 1; 317 else { 318 optlen = cp[1]; 319 if (optlen <= 0) 320 break; 321 } 322 323 switch (opt) { 324 325 default: 326 break; 327 328 case TCPOPT_MAXSEG: 329 bits |= IP_FW_TCPOPT_MSS; 330 break; 331 332 case TCPOPT_WINDOW: 333 bits |= IP_FW_TCPOPT_WINDOW; 334 break; 335 336 case TCPOPT_SACK_PERMITTED: 337 case TCPOPT_SACK: 338 bits |= IP_FW_TCPOPT_SACK; 339 break; 340 341 case TCPOPT_TIMESTAMP: 342 bits |= IP_FW_TCPOPT_TS; 343 break; 344 345 } 346 } 347 return (flags_match(cmd, bits)); 348 } 349 350 static int 351 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, uint32_t *tablearg) 352 { 353 if (ifp == NULL) /* no iface with this packet, match fails */ 354 return 0; 355 /* Check by name or by IP address */ 356 if (cmd->name[0] != '\0') { /* match by name */ 357 if (cmd->name[0] == '\1') /* use tablearg to match */ 358 return ipfw_lookup_table_extended(chain, cmd->p.glob, 359 ifp->if_xname, tablearg, IPFW_TABLE_INTERFACE); 360 /* Check name */ 361 if (cmd->p.glob) { 362 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 363 return(1); 364 } else { 365 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 366 return(1); 367 } 368 } else { 369 #ifdef __FreeBSD__ /* and OSX too ? */ 370 struct ifaddr *ia; 371 372 if_addr_rlock(ifp); 373 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 374 if (ia->ifa_addr->sa_family != AF_INET) 375 continue; 376 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 377 (ia->ifa_addr))->sin_addr.s_addr) { 378 if_addr_runlock(ifp); 379 return(1); /* match */ 380 } 381 } 382 if_addr_runlock(ifp); 383 #endif /* __FreeBSD__ */ 384 } 385 return(0); /* no match, fail ... */ 386 } 387 388 /* 389 * The verify_path function checks if a route to the src exists and 390 * if it is reachable via ifp (when provided). 391 * 392 * The 'verrevpath' option checks that the interface that an IP packet 393 * arrives on is the same interface that traffic destined for the 394 * packet's source address would be routed out of. 395 * The 'versrcreach' option just checks that the source address is 396 * reachable via any route (except default) in the routing table. 397 * These two are a measure to block forged packets. This is also 398 * commonly known as "anti-spoofing" or Unicast Reverse Path 399 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 400 * is purposely reminiscent of the Cisco IOS command, 401 * 402 * ip verify unicast reverse-path 403 * ip verify unicast source reachable-via any 404 * 405 * which implements the same functionality. But note that the syntax 406 * is misleading, and the check may be performed on all IP packets 407 * whether unicast, multicast, or broadcast. 408 */ 409 static int 410 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 411 { 412 #ifndef __FreeBSD__ 413 return 0; 414 #else 415 struct route ro; 416 struct sockaddr_in *dst; 417 418 bzero(&ro, sizeof(ro)); 419 420 dst = (struct sockaddr_in *)&(ro.ro_dst); 421 dst->sin_family = AF_INET; 422 dst->sin_len = sizeof(*dst); 423 dst->sin_addr = src; 424 in_rtalloc_ign(&ro, 0, fib); 425 426 if (ro.ro_rt == NULL) 427 return 0; 428 429 /* 430 * If ifp is provided, check for equality with rtentry. 431 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 432 * in order to pass packets injected back by if_simloop(): 433 * if useloopback == 1 routing entry (via lo0) for our own address 434 * may exist, so we need to handle routing assymetry. 435 */ 436 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 437 RTFREE(ro.ro_rt); 438 return 0; 439 } 440 441 /* if no ifp provided, check if rtentry is not default route */ 442 if (ifp == NULL && 443 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 444 RTFREE(ro.ro_rt); 445 return 0; 446 } 447 448 /* or if this is a blackhole/reject route */ 449 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 450 RTFREE(ro.ro_rt); 451 return 0; 452 } 453 454 /* found valid route */ 455 RTFREE(ro.ro_rt); 456 return 1; 457 #endif /* __FreeBSD__ */ 458 } 459 460 #ifdef INET6 461 /* 462 * ipv6 specific rules here... 463 */ 464 static __inline int 465 icmp6type_match (int type, ipfw_insn_u32 *cmd) 466 { 467 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 468 } 469 470 static int 471 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 472 { 473 int i; 474 for (i=0; i <= cmd->o.arg1; ++i ) 475 if (curr_flow == cmd->d[i] ) 476 return 1; 477 return 0; 478 } 479 480 /* support for IP6_*_ME opcodes */ 481 static int 482 search_ip6_addr_net (struct in6_addr * ip6_addr) 483 { 484 struct ifnet *mdc; 485 struct ifaddr *mdc2; 486 struct in6_ifaddr *fdm; 487 struct in6_addr copia; 488 489 TAILQ_FOREACH(mdc, &V_ifnet, if_link) { 490 if_addr_rlock(mdc); 491 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) { 492 if (mdc2->ifa_addr->sa_family == AF_INET6) { 493 fdm = (struct in6_ifaddr *)mdc2; 494 copia = fdm->ia_addr.sin6_addr; 495 /* need for leaving scope_id in the sock_addr */ 496 in6_clearscope(&copia); 497 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) { 498 if_addr_runlock(mdc); 499 return 1; 500 } 501 } 502 } 503 if_addr_runlock(mdc); 504 } 505 return 0; 506 } 507 508 static int 509 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 510 { 511 struct route_in6 ro; 512 struct sockaddr_in6 *dst; 513 514 bzero(&ro, sizeof(ro)); 515 516 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 517 dst->sin6_family = AF_INET6; 518 dst->sin6_len = sizeof(*dst); 519 dst->sin6_addr = *src; 520 521 in6_rtalloc_ign(&ro, 0, fib); 522 if (ro.ro_rt == NULL) 523 return 0; 524 525 /* 526 * if ifp is provided, check for equality with rtentry 527 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 528 * to support the case of sending packets to an address of our own. 529 * (where the former interface is the first argument of if_simloop() 530 * (=ifp), the latter is lo0) 531 */ 532 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 533 RTFREE(ro.ro_rt); 534 return 0; 535 } 536 537 /* if no ifp provided, check if rtentry is not default route */ 538 if (ifp == NULL && 539 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 540 RTFREE(ro.ro_rt); 541 return 0; 542 } 543 544 /* or if this is a blackhole/reject route */ 545 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 546 RTFREE(ro.ro_rt); 547 return 0; 548 } 549 550 /* found valid route */ 551 RTFREE(ro.ro_rt); 552 return 1; 553 554 } 555 556 static int 557 is_icmp6_query(int icmp6_type) 558 { 559 if ((icmp6_type <= ICMP6_MAXTYPE) && 560 (icmp6_type == ICMP6_ECHO_REQUEST || 561 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 562 icmp6_type == ICMP6_WRUREQUEST || 563 icmp6_type == ICMP6_FQDN_QUERY || 564 icmp6_type == ICMP6_NI_QUERY)) 565 return (1); 566 567 return (0); 568 } 569 570 static void 571 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 572 { 573 struct mbuf *m; 574 575 m = args->m; 576 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 577 struct tcphdr *tcp; 578 tcp = (struct tcphdr *)((char *)ip6 + hlen); 579 580 if ((tcp->th_flags & TH_RST) == 0) { 581 struct mbuf *m0; 582 m0 = ipfw_send_pkt(args->m, &(args->f_id), 583 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 584 tcp->th_flags | TH_RST); 585 if (m0 != NULL) 586 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 587 NULL); 588 } 589 FREE_PKT(m); 590 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 591 #if 0 592 /* 593 * Unlike above, the mbufs need to line up with the ip6 hdr, 594 * as the contents are read. We need to m_adj() the 595 * needed amount. 596 * The mbuf will however be thrown away so we can adjust it. 597 * Remember we did an m_pullup on it already so we 598 * can make some assumptions about contiguousness. 599 */ 600 if (args->L3offset) 601 m_adj(m, args->L3offset); 602 #endif 603 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 604 } else 605 FREE_PKT(m); 606 607 args->m = NULL; 608 } 609 610 #endif /* INET6 */ 611 612 613 /* 614 * sends a reject message, consuming the mbuf passed as an argument. 615 */ 616 static void 617 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 618 { 619 620 #if 0 621 /* XXX When ip is not guaranteed to be at mtod() we will 622 * need to account for this */ 623 * The mbuf will however be thrown away so we can adjust it. 624 * Remember we did an m_pullup on it already so we 625 * can make some assumptions about contiguousness. 626 */ 627 if (args->L3offset) 628 m_adj(m, args->L3offset); 629 #endif 630 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 631 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 632 } else if (args->f_id.proto == IPPROTO_TCP) { 633 struct tcphdr *const tcp = 634 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 635 if ( (tcp->th_flags & TH_RST) == 0) { 636 struct mbuf *m; 637 m = ipfw_send_pkt(args->m, &(args->f_id), 638 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 639 tcp->th_flags | TH_RST); 640 if (m != NULL) 641 ip_output(m, NULL, NULL, 0, NULL, NULL); 642 } 643 FREE_PKT(args->m); 644 } else 645 FREE_PKT(args->m); 646 args->m = NULL; 647 } 648 649 /* 650 * Support for uid/gid/jail lookup. These tests are expensive 651 * (because we may need to look into the list of active sockets) 652 * so we cache the results. ugid_lookupp is 0 if we have not 653 * yet done a lookup, 1 if we succeeded, and -1 if we tried 654 * and failed. The function always returns the match value. 655 * We could actually spare the variable and use *uc, setting 656 * it to '(void *)check_uidgid if we have no info, NULL if 657 * we tried and failed, or any other value if successful. 658 */ 659 static int 660 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 661 struct ucred **uc) 662 { 663 #ifndef __FreeBSD__ 664 /* XXX */ 665 return cred_check(insn, proto, oif, 666 dst_ip, dst_port, src_ip, src_port, 667 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 668 #else /* FreeBSD */ 669 struct in_addr src_ip, dst_ip; 670 struct inpcbinfo *pi; 671 struct ipfw_flow_id *id; 672 struct inpcb *pcb, *inp; 673 struct ifnet *oif; 674 int lookupflags; 675 int match; 676 677 id = &args->f_id; 678 inp = args->inp; 679 oif = args->oif; 680 681 /* 682 * Check to see if the UDP or TCP stack supplied us with 683 * the PCB. If so, rather then holding a lock and looking 684 * up the PCB, we can use the one that was supplied. 685 */ 686 if (inp && *ugid_lookupp == 0) { 687 INP_LOCK_ASSERT(inp); 688 if (inp->inp_socket != NULL) { 689 *uc = crhold(inp->inp_cred); 690 *ugid_lookupp = 1; 691 } else 692 *ugid_lookupp = -1; 693 } 694 /* 695 * If we have already been here and the packet has no 696 * PCB entry associated with it, then we can safely 697 * assume that this is a no match. 698 */ 699 if (*ugid_lookupp == -1) 700 return (0); 701 if (id->proto == IPPROTO_TCP) { 702 lookupflags = 0; 703 pi = &V_tcbinfo; 704 } else if (id->proto == IPPROTO_UDP) { 705 lookupflags = INPLOOKUP_WILDCARD; 706 pi = &V_udbinfo; 707 } else 708 return 0; 709 lookupflags |= INPLOOKUP_RLOCKPCB; 710 match = 0; 711 if (*ugid_lookupp == 0) { 712 if (id->addr_type == 6) { 713 #ifdef INET6 714 if (oif == NULL) 715 pcb = in6_pcblookup_mbuf(pi, 716 &id->src_ip6, htons(id->src_port), 717 &id->dst_ip6, htons(id->dst_port), 718 lookupflags, oif, args->m); 719 else 720 pcb = in6_pcblookup_mbuf(pi, 721 &id->dst_ip6, htons(id->dst_port), 722 &id->src_ip6, htons(id->src_port), 723 lookupflags, oif, args->m); 724 #else 725 *ugid_lookupp = -1; 726 return (0); 727 #endif 728 } else { 729 src_ip.s_addr = htonl(id->src_ip); 730 dst_ip.s_addr = htonl(id->dst_ip); 731 if (oif == NULL) 732 pcb = in_pcblookup_mbuf(pi, 733 src_ip, htons(id->src_port), 734 dst_ip, htons(id->dst_port), 735 lookupflags, oif, args->m); 736 else 737 pcb = in_pcblookup_mbuf(pi, 738 dst_ip, htons(id->dst_port), 739 src_ip, htons(id->src_port), 740 lookupflags, oif, args->m); 741 } 742 if (pcb != NULL) { 743 INP_RLOCK_ASSERT(pcb); 744 *uc = crhold(pcb->inp_cred); 745 *ugid_lookupp = 1; 746 INP_RUNLOCK(pcb); 747 } 748 if (*ugid_lookupp == 0) { 749 /* 750 * We tried and failed, set the variable to -1 751 * so we will not try again on this packet. 752 */ 753 *ugid_lookupp = -1; 754 return (0); 755 } 756 } 757 if (insn->o.opcode == O_UID) 758 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 759 else if (insn->o.opcode == O_GID) 760 match = groupmember((gid_t)insn->d[0], *uc); 761 else if (insn->o.opcode == O_JAIL) 762 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 763 return (match); 764 #endif /* __FreeBSD__ */ 765 } 766 767 /* 768 * Helper function to set args with info on the rule after the matching 769 * one. slot is precise, whereas we guess rule_id as they are 770 * assigned sequentially. 771 */ 772 static inline void 773 set_match(struct ip_fw_args *args, int slot, 774 struct ip_fw_chain *chain) 775 { 776 args->rule.chain_id = chain->id; 777 args->rule.slot = slot + 1; /* we use 0 as a marker */ 778 args->rule.rule_id = 1 + chain->map[slot]->id; 779 args->rule.rulenum = chain->map[slot]->rulenum; 780 } 781 782 /* 783 * The main check routine for the firewall. 784 * 785 * All arguments are in args so we can modify them and return them 786 * back to the caller. 787 * 788 * Parameters: 789 * 790 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 791 * Starts with the IP header. 792 * args->eh (in) Mac header if present, NULL for layer3 packet. 793 * args->L3offset Number of bytes bypassed if we came from L2. 794 * e.g. often sizeof(eh) ** NOTYET ** 795 * args->oif Outgoing interface, NULL if packet is incoming. 796 * The incoming interface is in the mbuf. (in) 797 * args->divert_rule (in/out) 798 * Skip up to the first rule past this rule number; 799 * upon return, non-zero port number for divert or tee. 800 * 801 * args->rule Pointer to the last matching rule (in/out) 802 * args->next_hop Socket we are forwarding to (out). 803 * args->next_hop6 IPv6 next hop we are forwarding to (out). 804 * args->f_id Addresses grabbed from the packet (out) 805 * args->rule.info a cookie depending on rule action 806 * 807 * Return value: 808 * 809 * IP_FW_PASS the packet must be accepted 810 * IP_FW_DENY the packet must be dropped 811 * IP_FW_DIVERT divert packet, port in m_tag 812 * IP_FW_TEE tee packet, port in m_tag 813 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 814 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 815 * args->rule contains the matching rule, 816 * args->rule.info has additional information. 817 * 818 */ 819 int 820 ipfw_chk(struct ip_fw_args *args) 821 { 822 823 /* 824 * Local variables holding state while processing a packet: 825 * 826 * IMPORTANT NOTE: to speed up the processing of rules, there 827 * are some assumption on the values of the variables, which 828 * are documented here. Should you change them, please check 829 * the implementation of the various instructions to make sure 830 * that they still work. 831 * 832 * args->eh The MAC header. It is non-null for a layer2 833 * packet, it is NULL for a layer-3 packet. 834 * **notyet** 835 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 836 * 837 * m | args->m Pointer to the mbuf, as received from the caller. 838 * It may change if ipfw_chk() does an m_pullup, or if it 839 * consumes the packet because it calls send_reject(). 840 * XXX This has to change, so that ipfw_chk() never modifies 841 * or consumes the buffer. 842 * ip is the beginning of the ip(4 or 6) header. 843 * Calculated by adding the L3offset to the start of data. 844 * (Until we start using L3offset, the packet is 845 * supposed to start with the ip header). 846 */ 847 struct mbuf *m = args->m; 848 struct ip *ip = mtod(m, struct ip *); 849 850 /* 851 * For rules which contain uid/gid or jail constraints, cache 852 * a copy of the users credentials after the pcb lookup has been 853 * executed. This will speed up the processing of rules with 854 * these types of constraints, as well as decrease contention 855 * on pcb related locks. 856 */ 857 #ifndef __FreeBSD__ 858 struct bsd_ucred ucred_cache; 859 #else 860 struct ucred *ucred_cache = NULL; 861 #endif 862 int ucred_lookup = 0; 863 864 /* 865 * oif | args->oif If NULL, ipfw_chk has been called on the 866 * inbound path (ether_input, ip_input). 867 * If non-NULL, ipfw_chk has been called on the outbound path 868 * (ether_output, ip_output). 869 */ 870 struct ifnet *oif = args->oif; 871 872 int f_pos = 0; /* index of current rule in the array */ 873 int retval = 0; 874 875 /* 876 * hlen The length of the IP header. 877 */ 878 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 879 880 /* 881 * offset The offset of a fragment. offset != 0 means that 882 * we have a fragment at this offset of an IPv4 packet. 883 * offset == 0 means that (if this is an IPv4 packet) 884 * this is the first or only fragment. 885 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 886 * or there is a single packet fragement (fragement header added 887 * without needed). We will treat a single packet fragment as if 888 * there was no fragment header (or log/block depending on the 889 * V_fw_permit_single_frag6 sysctl setting). 890 */ 891 u_short offset = 0; 892 u_short ip6f_mf = 0; 893 894 /* 895 * Local copies of addresses. They are only valid if we have 896 * an IP packet. 897 * 898 * proto The protocol. Set to 0 for non-ip packets, 899 * or to the protocol read from the packet otherwise. 900 * proto != 0 means that we have an IPv4 packet. 901 * 902 * src_port, dst_port port numbers, in HOST format. Only 903 * valid for TCP and UDP packets. 904 * 905 * src_ip, dst_ip ip addresses, in NETWORK format. 906 * Only valid for IPv4 packets. 907 */ 908 uint8_t proto; 909 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 910 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 911 uint16_t iplen=0; 912 int pktlen; 913 uint16_t etype = 0; /* Host order stored ether type */ 914 915 /* 916 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 917 * MATCH_NONE when checked and not matched (q = NULL), 918 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 919 */ 920 int dyn_dir = MATCH_UNKNOWN; 921 ipfw_dyn_rule *q = NULL; 922 struct ip_fw_chain *chain = &V_layer3_chain; 923 924 /* 925 * We store in ulp a pointer to the upper layer protocol header. 926 * In the ipv4 case this is easy to determine from the header, 927 * but for ipv6 we might have some additional headers in the middle. 928 * ulp is NULL if not found. 929 */ 930 void *ulp = NULL; /* upper layer protocol pointer. */ 931 932 /* XXX ipv6 variables */ 933 int is_ipv6 = 0; 934 uint8_t icmp6_type = 0; 935 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 936 /* end of ipv6 variables */ 937 938 int is_ipv4 = 0; 939 940 int done = 0; /* flag to exit the outer loop */ 941 942 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 943 return (IP_FW_PASS); /* accept */ 944 945 dst_ip.s_addr = 0; /* make sure it is initialized */ 946 src_ip.s_addr = 0; /* make sure it is initialized */ 947 pktlen = m->m_pkthdr.len; 948 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 949 proto = args->f_id.proto = 0; /* mark f_id invalid */ 950 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 951 952 /* 953 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 954 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 955 * pointer might become stale after other pullups (but we never use it 956 * this way). 957 */ 958 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 959 #define PULLUP_LEN(_len, p, T) \ 960 do { \ 961 int x = (_len) + T; \ 962 if ((m)->m_len < x) { \ 963 args->m = m = m_pullup(m, x); \ 964 if (m == NULL) \ 965 goto pullup_failed; \ 966 } \ 967 p = (mtod(m, char *) + (_len)); \ 968 } while (0) 969 970 /* 971 * if we have an ether header, 972 */ 973 if (args->eh) 974 etype = ntohs(args->eh->ether_type); 975 976 /* Identify IP packets and fill up variables. */ 977 if (pktlen >= sizeof(struct ip6_hdr) && 978 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 979 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 980 is_ipv6 = 1; 981 args->f_id.addr_type = 6; 982 hlen = sizeof(struct ip6_hdr); 983 proto = ip6->ip6_nxt; 984 985 /* Search extension headers to find upper layer protocols */ 986 while (ulp == NULL && offset == 0) { 987 switch (proto) { 988 case IPPROTO_ICMPV6: 989 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 990 icmp6_type = ICMP6(ulp)->icmp6_type; 991 break; 992 993 case IPPROTO_TCP: 994 PULLUP_TO(hlen, ulp, struct tcphdr); 995 dst_port = TCP(ulp)->th_dport; 996 src_port = TCP(ulp)->th_sport; 997 /* save flags for dynamic rules */ 998 args->f_id._flags = TCP(ulp)->th_flags; 999 break; 1000 1001 case IPPROTO_SCTP: 1002 PULLUP_TO(hlen, ulp, struct sctphdr); 1003 src_port = SCTP(ulp)->src_port; 1004 dst_port = SCTP(ulp)->dest_port; 1005 break; 1006 1007 case IPPROTO_UDP: 1008 PULLUP_TO(hlen, ulp, struct udphdr); 1009 dst_port = UDP(ulp)->uh_dport; 1010 src_port = UDP(ulp)->uh_sport; 1011 break; 1012 1013 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1014 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1015 ext_hd |= EXT_HOPOPTS; 1016 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1017 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1018 ulp = NULL; 1019 break; 1020 1021 case IPPROTO_ROUTING: /* RFC 2460 */ 1022 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1023 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1024 case 0: 1025 ext_hd |= EXT_RTHDR0; 1026 break; 1027 case 2: 1028 ext_hd |= EXT_RTHDR2; 1029 break; 1030 default: 1031 if (V_fw_verbose) 1032 printf("IPFW2: IPV6 - Unknown " 1033 "Routing Header type(%d)\n", 1034 ((struct ip6_rthdr *) 1035 ulp)->ip6r_type); 1036 if (V_fw_deny_unknown_exthdrs) 1037 return (IP_FW_DENY); 1038 break; 1039 } 1040 ext_hd |= EXT_ROUTING; 1041 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1042 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1043 ulp = NULL; 1044 break; 1045 1046 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1047 PULLUP_TO(hlen, ulp, struct ip6_frag); 1048 ext_hd |= EXT_FRAGMENT; 1049 hlen += sizeof (struct ip6_frag); 1050 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1051 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1052 IP6F_OFF_MASK; 1053 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1054 IP6F_MORE_FRAG; 1055 if (V_fw_permit_single_frag6 == 0 && 1056 offset == 0 && ip6f_mf == 0) { 1057 if (V_fw_verbose) 1058 printf("IPFW2: IPV6 - Invalid " 1059 "Fragment Header\n"); 1060 if (V_fw_deny_unknown_exthdrs) 1061 return (IP_FW_DENY); 1062 break; 1063 } 1064 args->f_id.extra = 1065 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1066 ulp = NULL; 1067 break; 1068 1069 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1070 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1071 ext_hd |= EXT_DSTOPTS; 1072 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1073 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1074 ulp = NULL; 1075 break; 1076 1077 case IPPROTO_AH: /* RFC 2402 */ 1078 PULLUP_TO(hlen, ulp, struct ip6_ext); 1079 ext_hd |= EXT_AH; 1080 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1081 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1082 ulp = NULL; 1083 break; 1084 1085 case IPPROTO_ESP: /* RFC 2406 */ 1086 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1087 /* Anything past Seq# is variable length and 1088 * data past this ext. header is encrypted. */ 1089 ext_hd |= EXT_ESP; 1090 break; 1091 1092 case IPPROTO_NONE: /* RFC 2460 */ 1093 /* 1094 * Packet ends here, and IPv6 header has 1095 * already been pulled up. If ip6e_len!=0 1096 * then octets must be ignored. 1097 */ 1098 ulp = ip; /* non-NULL to get out of loop. */ 1099 break; 1100 1101 case IPPROTO_OSPFIGP: 1102 /* XXX OSPF header check? */ 1103 PULLUP_TO(hlen, ulp, struct ip6_ext); 1104 break; 1105 1106 case IPPROTO_PIM: 1107 /* XXX PIM header check? */ 1108 PULLUP_TO(hlen, ulp, struct pim); 1109 break; 1110 1111 case IPPROTO_CARP: 1112 PULLUP_TO(hlen, ulp, struct carp_header); 1113 if (((struct carp_header *)ulp)->carp_version != 1114 CARP_VERSION) 1115 return (IP_FW_DENY); 1116 if (((struct carp_header *)ulp)->carp_type != 1117 CARP_ADVERTISEMENT) 1118 return (IP_FW_DENY); 1119 break; 1120 1121 case IPPROTO_IPV6: /* RFC 2893 */ 1122 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1123 break; 1124 1125 case IPPROTO_IPV4: /* RFC 2893 */ 1126 PULLUP_TO(hlen, ulp, struct ip); 1127 break; 1128 1129 default: 1130 if (V_fw_verbose) 1131 printf("IPFW2: IPV6 - Unknown " 1132 "Extension Header(%d), ext_hd=%x\n", 1133 proto, ext_hd); 1134 if (V_fw_deny_unknown_exthdrs) 1135 return (IP_FW_DENY); 1136 PULLUP_TO(hlen, ulp, struct ip6_ext); 1137 break; 1138 } /*switch */ 1139 } 1140 ip = mtod(m, struct ip *); 1141 ip6 = (struct ip6_hdr *)ip; 1142 args->f_id.src_ip6 = ip6->ip6_src; 1143 args->f_id.dst_ip6 = ip6->ip6_dst; 1144 args->f_id.src_ip = 0; 1145 args->f_id.dst_ip = 0; 1146 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1147 } else if (pktlen >= sizeof(struct ip) && 1148 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1149 is_ipv4 = 1; 1150 hlen = ip->ip_hl << 2; 1151 args->f_id.addr_type = 4; 1152 1153 /* 1154 * Collect parameters into local variables for faster matching. 1155 */ 1156 proto = ip->ip_p; 1157 src_ip = ip->ip_src; 1158 dst_ip = ip->ip_dst; 1159 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1160 iplen = ntohs(ip->ip_len); 1161 pktlen = iplen < pktlen ? iplen : pktlen; 1162 1163 if (offset == 0) { 1164 switch (proto) { 1165 case IPPROTO_TCP: 1166 PULLUP_TO(hlen, ulp, struct tcphdr); 1167 dst_port = TCP(ulp)->th_dport; 1168 src_port = TCP(ulp)->th_sport; 1169 /* save flags for dynamic rules */ 1170 args->f_id._flags = TCP(ulp)->th_flags; 1171 break; 1172 1173 case IPPROTO_SCTP: 1174 PULLUP_TO(hlen, ulp, struct sctphdr); 1175 src_port = SCTP(ulp)->src_port; 1176 dst_port = SCTP(ulp)->dest_port; 1177 break; 1178 1179 case IPPROTO_UDP: 1180 PULLUP_TO(hlen, ulp, struct udphdr); 1181 dst_port = UDP(ulp)->uh_dport; 1182 src_port = UDP(ulp)->uh_sport; 1183 break; 1184 1185 case IPPROTO_ICMP: 1186 PULLUP_TO(hlen, ulp, struct icmphdr); 1187 //args->f_id.flags = ICMP(ulp)->icmp_type; 1188 break; 1189 1190 default: 1191 break; 1192 } 1193 } 1194 1195 ip = mtod(m, struct ip *); 1196 args->f_id.src_ip = ntohl(src_ip.s_addr); 1197 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1198 } 1199 #undef PULLUP_TO 1200 if (proto) { /* we may have port numbers, store them */ 1201 args->f_id.proto = proto; 1202 args->f_id.src_port = src_port = ntohs(src_port); 1203 args->f_id.dst_port = dst_port = ntohs(dst_port); 1204 } 1205 1206 IPFW_RLOCK(chain); 1207 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1208 IPFW_RUNLOCK(chain); 1209 return (IP_FW_PASS); /* accept */ 1210 } 1211 if (args->rule.slot) { 1212 /* 1213 * Packet has already been tagged as a result of a previous 1214 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1215 * REASS, NETGRAPH, DIVERT/TEE...) 1216 * Validate the slot and continue from the next one 1217 * if still present, otherwise do a lookup. 1218 */ 1219 f_pos = (args->rule.chain_id == chain->id) ? 1220 args->rule.slot : 1221 ipfw_find_rule(chain, args->rule.rulenum, 1222 args->rule.rule_id); 1223 } else { 1224 f_pos = 0; 1225 } 1226 1227 /* 1228 * Now scan the rules, and parse microinstructions for each rule. 1229 * We have two nested loops and an inner switch. Sometimes we 1230 * need to break out of one or both loops, or re-enter one of 1231 * the loops with updated variables. Loop variables are: 1232 * 1233 * f_pos (outer loop) points to the current rule. 1234 * On output it points to the matching rule. 1235 * done (outer loop) is used as a flag to break the loop. 1236 * l (inner loop) residual length of current rule. 1237 * cmd points to the current microinstruction. 1238 * 1239 * We break the inner loop by setting l=0 and possibly 1240 * cmdlen=0 if we don't want to advance cmd. 1241 * We break the outer loop by setting done=1 1242 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1243 * as needed. 1244 */ 1245 for (; f_pos < chain->n_rules; f_pos++) { 1246 ipfw_insn *cmd; 1247 uint32_t tablearg = 0; 1248 int l, cmdlen, skip_or; /* skip rest of OR block */ 1249 struct ip_fw *f; 1250 1251 f = chain->map[f_pos]; 1252 if (V_set_disable & (1 << f->set) ) 1253 continue; 1254 1255 skip_or = 0; 1256 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1257 l -= cmdlen, cmd += cmdlen) { 1258 int match; 1259 1260 /* 1261 * check_body is a jump target used when we find a 1262 * CHECK_STATE, and need to jump to the body of 1263 * the target rule. 1264 */ 1265 1266 /* check_body: */ 1267 cmdlen = F_LEN(cmd); 1268 /* 1269 * An OR block (insn_1 || .. || insn_n) has the 1270 * F_OR bit set in all but the last instruction. 1271 * The first match will set "skip_or", and cause 1272 * the following instructions to be skipped until 1273 * past the one with the F_OR bit clear. 1274 */ 1275 if (skip_or) { /* skip this instruction */ 1276 if ((cmd->len & F_OR) == 0) 1277 skip_or = 0; /* next one is good */ 1278 continue; 1279 } 1280 match = 0; /* set to 1 if we succeed */ 1281 1282 switch (cmd->opcode) { 1283 /* 1284 * The first set of opcodes compares the packet's 1285 * fields with some pattern, setting 'match' if a 1286 * match is found. At the end of the loop there is 1287 * logic to deal with F_NOT and F_OR flags associated 1288 * with the opcode. 1289 */ 1290 case O_NOP: 1291 match = 1; 1292 break; 1293 1294 case O_FORWARD_MAC: 1295 printf("ipfw: opcode %d unimplemented\n", 1296 cmd->opcode); 1297 break; 1298 1299 case O_GID: 1300 case O_UID: 1301 case O_JAIL: 1302 /* 1303 * We only check offset == 0 && proto != 0, 1304 * as this ensures that we have a 1305 * packet with the ports info. 1306 */ 1307 if (offset != 0) 1308 break; 1309 if (proto == IPPROTO_TCP || 1310 proto == IPPROTO_UDP) 1311 match = check_uidgid( 1312 (ipfw_insn_u32 *)cmd, 1313 args, &ucred_lookup, 1314 #ifdef __FreeBSD__ 1315 &ucred_cache); 1316 #else 1317 (void *)&ucred_cache); 1318 #endif 1319 break; 1320 1321 case O_RECV: 1322 match = iface_match(m->m_pkthdr.rcvif, 1323 (ipfw_insn_if *)cmd, chain, &tablearg); 1324 break; 1325 1326 case O_XMIT: 1327 match = iface_match(oif, (ipfw_insn_if *)cmd, 1328 chain, &tablearg); 1329 break; 1330 1331 case O_VIA: 1332 match = iface_match(oif ? oif : 1333 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1334 chain, &tablearg); 1335 break; 1336 1337 case O_MACADDR2: 1338 if (args->eh != NULL) { /* have MAC header */ 1339 u_int32_t *want = (u_int32_t *) 1340 ((ipfw_insn_mac *)cmd)->addr; 1341 u_int32_t *mask = (u_int32_t *) 1342 ((ipfw_insn_mac *)cmd)->mask; 1343 u_int32_t *hdr = (u_int32_t *)args->eh; 1344 1345 match = 1346 ( want[0] == (hdr[0] & mask[0]) && 1347 want[1] == (hdr[1] & mask[1]) && 1348 want[2] == (hdr[2] & mask[2]) ); 1349 } 1350 break; 1351 1352 case O_MAC_TYPE: 1353 if (args->eh != NULL) { 1354 u_int16_t *p = 1355 ((ipfw_insn_u16 *)cmd)->ports; 1356 int i; 1357 1358 for (i = cmdlen - 1; !match && i>0; 1359 i--, p += 2) 1360 match = (etype >= p[0] && 1361 etype <= p[1]); 1362 } 1363 break; 1364 1365 case O_FRAG: 1366 match = (offset != 0); 1367 break; 1368 1369 case O_IN: /* "out" is "not in" */ 1370 match = (oif == NULL); 1371 break; 1372 1373 case O_LAYER2: 1374 match = (args->eh != NULL); 1375 break; 1376 1377 case O_DIVERTED: 1378 { 1379 /* For diverted packets, args->rule.info 1380 * contains the divert port (in host format) 1381 * reason and direction. 1382 */ 1383 uint32_t i = args->rule.info; 1384 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1385 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1386 } 1387 break; 1388 1389 case O_PROTO: 1390 /* 1391 * We do not allow an arg of 0 so the 1392 * check of "proto" only suffices. 1393 */ 1394 match = (proto == cmd->arg1); 1395 break; 1396 1397 case O_IP_SRC: 1398 match = is_ipv4 && 1399 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1400 src_ip.s_addr); 1401 break; 1402 1403 case O_IP_SRC_LOOKUP: 1404 case O_IP_DST_LOOKUP: 1405 if (is_ipv4) { 1406 uint32_t key = 1407 (cmd->opcode == O_IP_DST_LOOKUP) ? 1408 dst_ip.s_addr : src_ip.s_addr; 1409 uint32_t v = 0; 1410 1411 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1412 /* generic lookup. The key must be 1413 * in 32bit big-endian format. 1414 */ 1415 v = ((ipfw_insn_u32 *)cmd)->d[1]; 1416 if (v == 0) 1417 key = dst_ip.s_addr; 1418 else if (v == 1) 1419 key = src_ip.s_addr; 1420 else if (v == 6) /* dscp */ 1421 key = (ip->ip_tos >> 2) & 0x3f; 1422 else if (offset != 0) 1423 break; 1424 else if (proto != IPPROTO_TCP && 1425 proto != IPPROTO_UDP) 1426 break; 1427 else if (v == 2) 1428 key = htonl(dst_port); 1429 else if (v == 3) 1430 key = htonl(src_port); 1431 else if (v == 4 || v == 5) { 1432 check_uidgid( 1433 (ipfw_insn_u32 *)cmd, 1434 args, &ucred_lookup, 1435 #ifdef __FreeBSD__ 1436 &ucred_cache); 1437 if (v == 4 /* O_UID */) 1438 key = ucred_cache->cr_uid; 1439 else if (v == 5 /* O_JAIL */) 1440 key = ucred_cache->cr_prison->pr_id; 1441 #else /* !__FreeBSD__ */ 1442 (void *)&ucred_cache); 1443 if (v ==4 /* O_UID */) 1444 key = ucred_cache.uid; 1445 else if (v == 5 /* O_JAIL */) 1446 key = ucred_cache.xid; 1447 #endif /* !__FreeBSD__ */ 1448 key = htonl(key); 1449 } else 1450 break; 1451 } 1452 match = ipfw_lookup_table(chain, 1453 cmd->arg1, key, &v); 1454 if (!match) 1455 break; 1456 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1457 match = 1458 ((ipfw_insn_u32 *)cmd)->d[0] == v; 1459 else 1460 tablearg = v; 1461 } else if (is_ipv6) { 1462 uint32_t v = 0; 1463 void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ? 1464 &args->f_id.dst_ip6: &args->f_id.src_ip6; 1465 match = ipfw_lookup_table_extended(chain, 1466 cmd->arg1, pkey, &v, 1467 IPFW_TABLE_CIDR); 1468 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1469 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1470 if (match) 1471 tablearg = v; 1472 } 1473 break; 1474 1475 case O_IP_SRC_MASK: 1476 case O_IP_DST_MASK: 1477 if (is_ipv4) { 1478 uint32_t a = 1479 (cmd->opcode == O_IP_DST_MASK) ? 1480 dst_ip.s_addr : src_ip.s_addr; 1481 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 1482 int i = cmdlen-1; 1483 1484 for (; !match && i>0; i-= 2, p+= 2) 1485 match = (p[0] == (a & p[1])); 1486 } 1487 break; 1488 1489 case O_IP_SRC_ME: 1490 if (is_ipv4) { 1491 struct ifnet *tif; 1492 1493 INADDR_TO_IFP(src_ip, tif); 1494 match = (tif != NULL); 1495 break; 1496 } 1497 #ifdef INET6 1498 /* FALLTHROUGH */ 1499 case O_IP6_SRC_ME: 1500 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 1501 #endif 1502 break; 1503 1504 case O_IP_DST_SET: 1505 case O_IP_SRC_SET: 1506 if (is_ipv4) { 1507 u_int32_t *d = (u_int32_t *)(cmd+1); 1508 u_int32_t addr = 1509 cmd->opcode == O_IP_DST_SET ? 1510 args->f_id.dst_ip : 1511 args->f_id.src_ip; 1512 1513 if (addr < d[0]) 1514 break; 1515 addr -= d[0]; /* subtract base */ 1516 match = (addr < cmd->arg1) && 1517 ( d[ 1 + (addr>>5)] & 1518 (1<<(addr & 0x1f)) ); 1519 } 1520 break; 1521 1522 case O_IP_DST: 1523 match = is_ipv4 && 1524 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1525 dst_ip.s_addr); 1526 break; 1527 1528 case O_IP_DST_ME: 1529 if (is_ipv4) { 1530 struct ifnet *tif; 1531 1532 INADDR_TO_IFP(dst_ip, tif); 1533 match = (tif != NULL); 1534 break; 1535 } 1536 #ifdef INET6 1537 /* FALLTHROUGH */ 1538 case O_IP6_DST_ME: 1539 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 1540 #endif 1541 break; 1542 1543 1544 case O_IP_SRCPORT: 1545 case O_IP_DSTPORT: 1546 /* 1547 * offset == 0 && proto != 0 is enough 1548 * to guarantee that we have a 1549 * packet with port info. 1550 */ 1551 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 1552 && offset == 0) { 1553 u_int16_t x = 1554 (cmd->opcode == O_IP_SRCPORT) ? 1555 src_port : dst_port ; 1556 u_int16_t *p = 1557 ((ipfw_insn_u16 *)cmd)->ports; 1558 int i; 1559 1560 for (i = cmdlen - 1; !match && i>0; 1561 i--, p += 2) 1562 match = (x>=p[0] && x<=p[1]); 1563 } 1564 break; 1565 1566 case O_ICMPTYPE: 1567 match = (offset == 0 && proto==IPPROTO_ICMP && 1568 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 1569 break; 1570 1571 #ifdef INET6 1572 case O_ICMP6TYPE: 1573 match = is_ipv6 && offset == 0 && 1574 proto==IPPROTO_ICMPV6 && 1575 icmp6type_match( 1576 ICMP6(ulp)->icmp6_type, 1577 (ipfw_insn_u32 *)cmd); 1578 break; 1579 #endif /* INET6 */ 1580 1581 case O_IPOPT: 1582 match = (is_ipv4 && 1583 ipopts_match(ip, cmd) ); 1584 break; 1585 1586 case O_IPVER: 1587 match = (is_ipv4 && 1588 cmd->arg1 == ip->ip_v); 1589 break; 1590 1591 case O_IPID: 1592 case O_IPLEN: 1593 case O_IPTTL: 1594 if (is_ipv4) { /* only for IP packets */ 1595 uint16_t x; 1596 uint16_t *p; 1597 int i; 1598 1599 if (cmd->opcode == O_IPLEN) 1600 x = iplen; 1601 else if (cmd->opcode == O_IPTTL) 1602 x = ip->ip_ttl; 1603 else /* must be IPID */ 1604 x = ntohs(ip->ip_id); 1605 if (cmdlen == 1) { 1606 match = (cmd->arg1 == x); 1607 break; 1608 } 1609 /* otherwise we have ranges */ 1610 p = ((ipfw_insn_u16 *)cmd)->ports; 1611 i = cmdlen - 1; 1612 for (; !match && i>0; i--, p += 2) 1613 match = (x >= p[0] && x <= p[1]); 1614 } 1615 break; 1616 1617 case O_IPPRECEDENCE: 1618 match = (is_ipv4 && 1619 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 1620 break; 1621 1622 case O_IPTOS: 1623 match = (is_ipv4 && 1624 flags_match(cmd, ip->ip_tos)); 1625 break; 1626 1627 case O_TCPDATALEN: 1628 if (proto == IPPROTO_TCP && offset == 0) { 1629 struct tcphdr *tcp; 1630 uint16_t x; 1631 uint16_t *p; 1632 int i; 1633 1634 tcp = TCP(ulp); 1635 x = iplen - 1636 ((ip->ip_hl + tcp->th_off) << 2); 1637 if (cmdlen == 1) { 1638 match = (cmd->arg1 == x); 1639 break; 1640 } 1641 /* otherwise we have ranges */ 1642 p = ((ipfw_insn_u16 *)cmd)->ports; 1643 i = cmdlen - 1; 1644 for (; !match && i>0; i--, p += 2) 1645 match = (x >= p[0] && x <= p[1]); 1646 } 1647 break; 1648 1649 case O_TCPFLAGS: 1650 match = (proto == IPPROTO_TCP && offset == 0 && 1651 flags_match(cmd, TCP(ulp)->th_flags)); 1652 break; 1653 1654 case O_TCPOPTS: 1655 PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2)); 1656 match = (proto == IPPROTO_TCP && offset == 0 && 1657 tcpopts_match(TCP(ulp), cmd)); 1658 break; 1659 1660 case O_TCPSEQ: 1661 match = (proto == IPPROTO_TCP && offset == 0 && 1662 ((ipfw_insn_u32 *)cmd)->d[0] == 1663 TCP(ulp)->th_seq); 1664 break; 1665 1666 case O_TCPACK: 1667 match = (proto == IPPROTO_TCP && offset == 0 && 1668 ((ipfw_insn_u32 *)cmd)->d[0] == 1669 TCP(ulp)->th_ack); 1670 break; 1671 1672 case O_TCPWIN: 1673 if (proto == IPPROTO_TCP && offset == 0) { 1674 uint16_t x; 1675 uint16_t *p; 1676 int i; 1677 1678 x = ntohs(TCP(ulp)->th_win); 1679 if (cmdlen == 1) { 1680 match = (cmd->arg1 == x); 1681 break; 1682 } 1683 /* Otherwise we have ranges. */ 1684 p = ((ipfw_insn_u16 *)cmd)->ports; 1685 i = cmdlen - 1; 1686 for (; !match && i > 0; i--, p += 2) 1687 match = (x >= p[0] && x <= p[1]); 1688 } 1689 break; 1690 1691 case O_ESTAB: 1692 /* reject packets which have SYN only */ 1693 /* XXX should i also check for TH_ACK ? */ 1694 match = (proto == IPPROTO_TCP && offset == 0 && 1695 (TCP(ulp)->th_flags & 1696 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 1697 break; 1698 1699 case O_ALTQ: { 1700 struct pf_mtag *at; 1701 struct m_tag *mtag; 1702 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 1703 1704 /* 1705 * ALTQ uses mbuf tags from another 1706 * packet filtering system - pf(4). 1707 * We allocate a tag in its format 1708 * and fill it in, pretending to be pf(4). 1709 */ 1710 match = 1; 1711 at = pf_find_mtag(m); 1712 if (at != NULL && at->qid != 0) 1713 break; 1714 mtag = m_tag_get(PACKET_TAG_PF, 1715 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 1716 if (mtag == NULL) { 1717 /* 1718 * Let the packet fall back to the 1719 * default ALTQ. 1720 */ 1721 break; 1722 } 1723 m_tag_prepend(m, mtag); 1724 at = (struct pf_mtag *)(mtag + 1); 1725 at->qid = altq->qid; 1726 at->hdr = ip; 1727 break; 1728 } 1729 1730 case O_LOG: 1731 ipfw_log(f, hlen, args, m, 1732 oif, offset | ip6f_mf, tablearg, ip); 1733 match = 1; 1734 break; 1735 1736 case O_PROB: 1737 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 1738 break; 1739 1740 case O_VERREVPATH: 1741 /* Outgoing packets automatically pass/match */ 1742 match = ((oif != NULL) || 1743 (m->m_pkthdr.rcvif == NULL) || 1744 ( 1745 #ifdef INET6 1746 is_ipv6 ? 1747 verify_path6(&(args->f_id.src_ip6), 1748 m->m_pkthdr.rcvif, args->f_id.fib) : 1749 #endif 1750 verify_path(src_ip, m->m_pkthdr.rcvif, 1751 args->f_id.fib))); 1752 break; 1753 1754 case O_VERSRCREACH: 1755 /* Outgoing packets automatically pass/match */ 1756 match = (hlen > 0 && ((oif != NULL) || 1757 #ifdef INET6 1758 is_ipv6 ? 1759 verify_path6(&(args->f_id.src_ip6), 1760 NULL, args->f_id.fib) : 1761 #endif 1762 verify_path(src_ip, NULL, args->f_id.fib))); 1763 break; 1764 1765 case O_ANTISPOOF: 1766 /* Outgoing packets automatically pass/match */ 1767 if (oif == NULL && hlen > 0 && 1768 ( (is_ipv4 && in_localaddr(src_ip)) 1769 #ifdef INET6 1770 || (is_ipv6 && 1771 in6_localaddr(&(args->f_id.src_ip6))) 1772 #endif 1773 )) 1774 match = 1775 #ifdef INET6 1776 is_ipv6 ? verify_path6( 1777 &(args->f_id.src_ip6), 1778 m->m_pkthdr.rcvif, 1779 args->f_id.fib) : 1780 #endif 1781 verify_path(src_ip, 1782 m->m_pkthdr.rcvif, 1783 args->f_id.fib); 1784 else 1785 match = 1; 1786 break; 1787 1788 case O_IPSEC: 1789 #ifdef IPSEC 1790 match = (m_tag_find(m, 1791 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 1792 #endif 1793 /* otherwise no match */ 1794 break; 1795 1796 #ifdef INET6 1797 case O_IP6_SRC: 1798 match = is_ipv6 && 1799 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 1800 &((ipfw_insn_ip6 *)cmd)->addr6); 1801 break; 1802 1803 case O_IP6_DST: 1804 match = is_ipv6 && 1805 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 1806 &((ipfw_insn_ip6 *)cmd)->addr6); 1807 break; 1808 case O_IP6_SRC_MASK: 1809 case O_IP6_DST_MASK: 1810 if (is_ipv6) { 1811 int i = cmdlen - 1; 1812 struct in6_addr p; 1813 struct in6_addr *d = 1814 &((ipfw_insn_ip6 *)cmd)->addr6; 1815 1816 for (; !match && i > 0; d += 2, 1817 i -= F_INSN_SIZE(struct in6_addr) 1818 * 2) { 1819 p = (cmd->opcode == 1820 O_IP6_SRC_MASK) ? 1821 args->f_id.src_ip6: 1822 args->f_id.dst_ip6; 1823 APPLY_MASK(&p, &d[1]); 1824 match = 1825 IN6_ARE_ADDR_EQUAL(&d[0], 1826 &p); 1827 } 1828 } 1829 break; 1830 1831 case O_FLOW6ID: 1832 match = is_ipv6 && 1833 flow6id_match(args->f_id.flow_id6, 1834 (ipfw_insn_u32 *) cmd); 1835 break; 1836 1837 case O_EXT_HDR: 1838 match = is_ipv6 && 1839 (ext_hd & ((ipfw_insn *) cmd)->arg1); 1840 break; 1841 1842 case O_IP6: 1843 match = is_ipv6; 1844 break; 1845 #endif 1846 1847 case O_IP4: 1848 match = is_ipv4; 1849 break; 1850 1851 case O_TAG: { 1852 struct m_tag *mtag; 1853 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 1854 tablearg : cmd->arg1; 1855 1856 /* Packet is already tagged with this tag? */ 1857 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 1858 1859 /* We have `untag' action when F_NOT flag is 1860 * present. And we must remove this mtag from 1861 * mbuf and reset `match' to zero (`match' will 1862 * be inversed later). 1863 * Otherwise we should allocate new mtag and 1864 * push it into mbuf. 1865 */ 1866 if (cmd->len & F_NOT) { /* `untag' action */ 1867 if (mtag != NULL) 1868 m_tag_delete(m, mtag); 1869 match = 0; 1870 } else { 1871 if (mtag == NULL) { 1872 mtag = m_tag_alloc( MTAG_IPFW, 1873 tag, 0, M_NOWAIT); 1874 if (mtag != NULL) 1875 m_tag_prepend(m, mtag); 1876 } 1877 match = 1; 1878 } 1879 break; 1880 } 1881 1882 case O_FIB: /* try match the specified fib */ 1883 if (args->f_id.fib == cmd->arg1) 1884 match = 1; 1885 break; 1886 1887 case O_SOCKARG: { 1888 struct inpcb *inp = args->inp; 1889 struct inpcbinfo *pi; 1890 1891 if (is_ipv6) /* XXX can we remove this ? */ 1892 break; 1893 1894 if (proto == IPPROTO_TCP) 1895 pi = &V_tcbinfo; 1896 else if (proto == IPPROTO_UDP) 1897 pi = &V_udbinfo; 1898 else 1899 break; 1900 1901 /* 1902 * XXXRW: so_user_cookie should almost 1903 * certainly be inp_user_cookie? 1904 */ 1905 1906 /* For incomming packet, lookup up the 1907 inpcb using the src/dest ip/port tuple */ 1908 if (inp == NULL) { 1909 inp = in_pcblookup(pi, 1910 src_ip, htons(src_port), 1911 dst_ip, htons(dst_port), 1912 INPLOOKUP_RLOCKPCB, NULL); 1913 if (inp != NULL) { 1914 tablearg = 1915 inp->inp_socket->so_user_cookie; 1916 if (tablearg) 1917 match = 1; 1918 INP_RUNLOCK(inp); 1919 } 1920 } else { 1921 if (inp->inp_socket) { 1922 tablearg = 1923 inp->inp_socket->so_user_cookie; 1924 if (tablearg) 1925 match = 1; 1926 } 1927 } 1928 break; 1929 } 1930 1931 case O_TAGGED: { 1932 struct m_tag *mtag; 1933 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 1934 tablearg : cmd->arg1; 1935 1936 if (cmdlen == 1) { 1937 match = m_tag_locate(m, MTAG_IPFW, 1938 tag, NULL) != NULL; 1939 break; 1940 } 1941 1942 /* we have ranges */ 1943 for (mtag = m_tag_first(m); 1944 mtag != NULL && !match; 1945 mtag = m_tag_next(m, mtag)) { 1946 uint16_t *p; 1947 int i; 1948 1949 if (mtag->m_tag_cookie != MTAG_IPFW) 1950 continue; 1951 1952 p = ((ipfw_insn_u16 *)cmd)->ports; 1953 i = cmdlen - 1; 1954 for(; !match && i > 0; i--, p += 2) 1955 match = 1956 mtag->m_tag_id >= p[0] && 1957 mtag->m_tag_id <= p[1]; 1958 } 1959 break; 1960 } 1961 1962 /* 1963 * The second set of opcodes represents 'actions', 1964 * i.e. the terminal part of a rule once the packet 1965 * matches all previous patterns. 1966 * Typically there is only one action for each rule, 1967 * and the opcode is stored at the end of the rule 1968 * (but there are exceptions -- see below). 1969 * 1970 * In general, here we set retval and terminate the 1971 * outer loop (would be a 'break 3' in some language, 1972 * but we need to set l=0, done=1) 1973 * 1974 * Exceptions: 1975 * O_COUNT and O_SKIPTO actions: 1976 * instead of terminating, we jump to the next rule 1977 * (setting l=0), or to the SKIPTO target (setting 1978 * f/f_len, cmd and l as needed), respectively. 1979 * 1980 * O_TAG, O_LOG and O_ALTQ action parameters: 1981 * perform some action and set match = 1; 1982 * 1983 * O_LIMIT and O_KEEP_STATE: these opcodes are 1984 * not real 'actions', and are stored right 1985 * before the 'action' part of the rule. 1986 * These opcodes try to install an entry in the 1987 * state tables; if successful, we continue with 1988 * the next opcode (match=1; break;), otherwise 1989 * the packet must be dropped (set retval, 1990 * break loops with l=0, done=1) 1991 * 1992 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 1993 * cause a lookup of the state table, and a jump 1994 * to the 'action' part of the parent rule 1995 * if an entry is found, or 1996 * (CHECK_STATE only) a jump to the next rule if 1997 * the entry is not found. 1998 * The result of the lookup is cached so that 1999 * further instances of these opcodes become NOPs. 2000 * The jump to the next rule is done by setting 2001 * l=0, cmdlen=0. 2002 */ 2003 case O_LIMIT: 2004 case O_KEEP_STATE: 2005 if (ipfw_install_state(f, 2006 (ipfw_insn_limit *)cmd, args, tablearg)) { 2007 /* error or limit violation */ 2008 retval = IP_FW_DENY; 2009 l = 0; /* exit inner loop */ 2010 done = 1; /* exit outer loop */ 2011 } 2012 match = 1; 2013 break; 2014 2015 case O_PROBE_STATE: 2016 case O_CHECK_STATE: 2017 /* 2018 * dynamic rules are checked at the first 2019 * keep-state or check-state occurrence, 2020 * with the result being stored in dyn_dir. 2021 * The compiler introduces a PROBE_STATE 2022 * instruction for us when we have a 2023 * KEEP_STATE (because PROBE_STATE needs 2024 * to be run first). 2025 */ 2026 if (dyn_dir == MATCH_UNKNOWN && 2027 (q = ipfw_lookup_dyn_rule(&args->f_id, 2028 &dyn_dir, proto == IPPROTO_TCP ? 2029 TCP(ulp) : NULL)) 2030 != NULL) { 2031 /* 2032 * Found dynamic entry, update stats 2033 * and jump to the 'action' part of 2034 * the parent rule by setting 2035 * f, cmd, l and clearing cmdlen. 2036 */ 2037 q->pcnt++; 2038 q->bcnt += pktlen; 2039 /* XXX we would like to have f_pos 2040 * readily accessible in the dynamic 2041 * rule, instead of having to 2042 * lookup q->rule. 2043 */ 2044 f = q->rule; 2045 f_pos = ipfw_find_rule(chain, 2046 f->rulenum, f->id); 2047 cmd = ACTION_PTR(f); 2048 l = f->cmd_len - f->act_ofs; 2049 ipfw_dyn_unlock(); 2050 cmdlen = 0; 2051 match = 1; 2052 break; 2053 } 2054 /* 2055 * Dynamic entry not found. If CHECK_STATE, 2056 * skip to next rule, if PROBE_STATE just 2057 * ignore and continue with next opcode. 2058 */ 2059 if (cmd->opcode == O_CHECK_STATE) 2060 l = 0; /* exit inner loop */ 2061 match = 1; 2062 break; 2063 2064 case O_ACCEPT: 2065 retval = 0; /* accept */ 2066 l = 0; /* exit inner loop */ 2067 done = 1; /* exit outer loop */ 2068 break; 2069 2070 case O_PIPE: 2071 case O_QUEUE: 2072 set_match(args, f_pos, chain); 2073 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ? 2074 tablearg : cmd->arg1; 2075 if (cmd->opcode == O_PIPE) 2076 args->rule.info |= IPFW_IS_PIPE; 2077 if (V_fw_one_pass) 2078 args->rule.info |= IPFW_ONEPASS; 2079 retval = IP_FW_DUMMYNET; 2080 l = 0; /* exit inner loop */ 2081 done = 1; /* exit outer loop */ 2082 break; 2083 2084 case O_DIVERT: 2085 case O_TEE: 2086 if (args->eh) /* not on layer 2 */ 2087 break; 2088 /* otherwise this is terminal */ 2089 l = 0; /* exit inner loop */ 2090 done = 1; /* exit outer loop */ 2091 retval = (cmd->opcode == O_DIVERT) ? 2092 IP_FW_DIVERT : IP_FW_TEE; 2093 set_match(args, f_pos, chain); 2094 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ? 2095 tablearg : cmd->arg1; 2096 break; 2097 2098 case O_COUNT: 2099 f->pcnt++; /* update stats */ 2100 f->bcnt += pktlen; 2101 f->timestamp = time_uptime; 2102 l = 0; /* exit inner loop */ 2103 break; 2104 2105 case O_SKIPTO: 2106 f->pcnt++; /* update stats */ 2107 f->bcnt += pktlen; 2108 f->timestamp = time_uptime; 2109 /* If possible use cached f_pos (in f->next_rule), 2110 * whose version is written in f->next_rule 2111 * (horrible hacks to avoid changing the ABI). 2112 */ 2113 if (cmd->arg1 != IP_FW_TABLEARG && 2114 (uintptr_t)f->x_next == chain->id) { 2115 f_pos = (uintptr_t)f->next_rule; 2116 } else { 2117 int i = (cmd->arg1 == IP_FW_TABLEARG) ? 2118 tablearg : cmd->arg1; 2119 /* make sure we do not jump backward */ 2120 if (i <= f->rulenum) 2121 i = f->rulenum + 1; 2122 f_pos = ipfw_find_rule(chain, i, 0); 2123 /* update the cache */ 2124 if (cmd->arg1 != IP_FW_TABLEARG) { 2125 f->next_rule = 2126 (void *)(uintptr_t)f_pos; 2127 f->x_next = 2128 (void *)(uintptr_t)chain->id; 2129 } 2130 } 2131 /* 2132 * Skip disabled rules, and re-enter 2133 * the inner loop with the correct 2134 * f_pos, f, l and cmd. 2135 * Also clear cmdlen and skip_or 2136 */ 2137 for (; f_pos < chain->n_rules - 1 && 2138 (V_set_disable & 2139 (1 << chain->map[f_pos]->set)); 2140 f_pos++) 2141 ; 2142 /* Re-enter the inner loop at the skipto rule. */ 2143 f = chain->map[f_pos]; 2144 l = f->cmd_len; 2145 cmd = f->cmd; 2146 match = 1; 2147 cmdlen = 0; 2148 skip_or = 0; 2149 continue; 2150 break; /* not reached */ 2151 2152 case O_CALLRETURN: { 2153 /* 2154 * Implementation of `subroutine' call/return, 2155 * in the stack carried in an mbuf tag. This 2156 * is different from `skipto' in that any call 2157 * address is possible (`skipto' must prevent 2158 * backward jumps to avoid endless loops). 2159 * We have `return' action when F_NOT flag is 2160 * present. The `m_tag_id' field is used as 2161 * stack pointer. 2162 */ 2163 struct m_tag *mtag; 2164 uint16_t jmpto, *stack; 2165 2166 #define IS_CALL ((cmd->len & F_NOT) == 0) 2167 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2168 /* 2169 * Hand-rolled version of m_tag_locate() with 2170 * wildcard `type'. 2171 * If not already tagged, allocate new tag. 2172 */ 2173 mtag = m_tag_first(m); 2174 while (mtag != NULL) { 2175 if (mtag->m_tag_cookie == 2176 MTAG_IPFW_CALL) 2177 break; 2178 mtag = m_tag_next(m, mtag); 2179 } 2180 if (mtag == NULL && IS_CALL) { 2181 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2182 IPFW_CALLSTACK_SIZE * 2183 sizeof(uint16_t), M_NOWAIT); 2184 if (mtag != NULL) 2185 m_tag_prepend(m, mtag); 2186 } 2187 2188 /* 2189 * On error both `call' and `return' just 2190 * continue with next rule. 2191 */ 2192 if (IS_RETURN && (mtag == NULL || 2193 mtag->m_tag_id == 0)) { 2194 l = 0; /* exit inner loop */ 2195 break; 2196 } 2197 if (IS_CALL && (mtag == NULL || 2198 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2199 printf("ipfw: call stack error, " 2200 "go to next rule\n"); 2201 l = 0; /* exit inner loop */ 2202 break; 2203 } 2204 2205 f->pcnt++; /* update stats */ 2206 f->bcnt += pktlen; 2207 f->timestamp = time_uptime; 2208 stack = (uint16_t *)(mtag + 1); 2209 2210 /* 2211 * The `call' action may use cached f_pos 2212 * (in f->next_rule), whose version is written 2213 * in f->next_rule. 2214 * The `return' action, however, doesn't have 2215 * fixed jump address in cmd->arg1 and can't use 2216 * cache. 2217 */ 2218 if (IS_CALL) { 2219 stack[mtag->m_tag_id] = f->rulenum; 2220 mtag->m_tag_id++; 2221 if (cmd->arg1 != IP_FW_TABLEARG && 2222 (uintptr_t)f->x_next == chain->id) { 2223 f_pos = (uintptr_t)f->next_rule; 2224 } else { 2225 jmpto = (cmd->arg1 == 2226 IP_FW_TABLEARG) ? tablearg: 2227 cmd->arg1; 2228 f_pos = ipfw_find_rule(chain, 2229 jmpto, 0); 2230 /* update the cache */ 2231 if (cmd->arg1 != 2232 IP_FW_TABLEARG) { 2233 f->next_rule = 2234 (void *)(uintptr_t) 2235 f_pos; 2236 f->x_next = 2237 (void *)(uintptr_t) 2238 chain->id; 2239 } 2240 } 2241 } else { /* `return' action */ 2242 mtag->m_tag_id--; 2243 jmpto = stack[mtag->m_tag_id] + 1; 2244 f_pos = ipfw_find_rule(chain, jmpto, 0); 2245 } 2246 2247 /* 2248 * Skip disabled rules, and re-enter 2249 * the inner loop with the correct 2250 * f_pos, f, l and cmd. 2251 * Also clear cmdlen and skip_or 2252 */ 2253 for (; f_pos < chain->n_rules - 1 && 2254 (V_set_disable & 2255 (1 << chain->map[f_pos]->set)); f_pos++) 2256 ; 2257 /* Re-enter the inner loop at the dest rule. */ 2258 f = chain->map[f_pos]; 2259 l = f->cmd_len; 2260 cmd = f->cmd; 2261 cmdlen = 0; 2262 skip_or = 0; 2263 continue; 2264 break; /* NOTREACHED */ 2265 } 2266 #undef IS_CALL 2267 #undef IS_RETURN 2268 2269 case O_REJECT: 2270 /* 2271 * Drop the packet and send a reject notice 2272 * if the packet is not ICMP (or is an ICMP 2273 * query), and it is not multicast/broadcast. 2274 */ 2275 if (hlen > 0 && is_ipv4 && offset == 0 && 2276 (proto != IPPROTO_ICMP || 2277 is_icmp_query(ICMP(ulp))) && 2278 !(m->m_flags & (M_BCAST|M_MCAST)) && 2279 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2280 send_reject(args, cmd->arg1, iplen, ip); 2281 m = args->m; 2282 } 2283 /* FALLTHROUGH */ 2284 #ifdef INET6 2285 case O_UNREACH6: 2286 if (hlen > 0 && is_ipv6 && 2287 ((offset & IP6F_OFF_MASK) == 0) && 2288 (proto != IPPROTO_ICMPV6 || 2289 (is_icmp6_query(icmp6_type) == 1)) && 2290 !(m->m_flags & (M_BCAST|M_MCAST)) && 2291 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2292 send_reject6( 2293 args, cmd->arg1, hlen, 2294 (struct ip6_hdr *)ip); 2295 m = args->m; 2296 } 2297 /* FALLTHROUGH */ 2298 #endif 2299 case O_DENY: 2300 retval = IP_FW_DENY; 2301 l = 0; /* exit inner loop */ 2302 done = 1; /* exit outer loop */ 2303 break; 2304 2305 case O_FORWARD_IP: 2306 if (args->eh) /* not valid on layer2 pkts */ 2307 break; 2308 if (q == NULL || q->rule != f || 2309 dyn_dir == MATCH_FORWARD) { 2310 struct sockaddr_in *sa; 2311 sa = &(((ipfw_insn_sa *)cmd)->sa); 2312 if (sa->sin_addr.s_addr == INADDR_ANY) { 2313 bcopy(sa, &args->hopstore, 2314 sizeof(*sa)); 2315 args->hopstore.sin_addr.s_addr = 2316 htonl(tablearg); 2317 args->next_hop = &args->hopstore; 2318 } else { 2319 args->next_hop = sa; 2320 } 2321 } 2322 retval = IP_FW_PASS; 2323 l = 0; /* exit inner loop */ 2324 done = 1; /* exit outer loop */ 2325 break; 2326 2327 #ifdef INET6 2328 case O_FORWARD_IP6: 2329 if (args->eh) /* not valid on layer2 pkts */ 2330 break; 2331 if (q == NULL || q->rule != f || 2332 dyn_dir == MATCH_FORWARD) { 2333 struct sockaddr_in6 *sin6; 2334 2335 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2336 args->next_hop6 = sin6; 2337 } 2338 retval = IP_FW_PASS; 2339 l = 0; /* exit inner loop */ 2340 done = 1; /* exit outer loop */ 2341 break; 2342 #endif 2343 2344 case O_NETGRAPH: 2345 case O_NGTEE: 2346 set_match(args, f_pos, chain); 2347 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ? 2348 tablearg : cmd->arg1; 2349 if (V_fw_one_pass) 2350 args->rule.info |= IPFW_ONEPASS; 2351 retval = (cmd->opcode == O_NETGRAPH) ? 2352 IP_FW_NETGRAPH : IP_FW_NGTEE; 2353 l = 0; /* exit inner loop */ 2354 done = 1; /* exit outer loop */ 2355 break; 2356 2357 case O_SETFIB: { 2358 uint32_t fib; 2359 2360 f->pcnt++; /* update stats */ 2361 f->bcnt += pktlen; 2362 f->timestamp = time_uptime; 2363 fib = (cmd->arg1 == IP_FW_TABLEARG) ? tablearg: 2364 cmd->arg1; 2365 if (fib >= rt_numfibs) 2366 fib = 0; 2367 M_SETFIB(m, fib); 2368 args->f_id.fib = fib; 2369 l = 0; /* exit inner loop */ 2370 break; 2371 } 2372 2373 case O_NAT: 2374 if (!IPFW_NAT_LOADED) { 2375 retval = IP_FW_DENY; 2376 } else { 2377 struct cfg_nat *t; 2378 int nat_id; 2379 2380 set_match(args, f_pos, chain); 2381 /* Check if this is 'global' nat rule */ 2382 if (cmd->arg1 == 0) { 2383 retval = ipfw_nat_ptr(args, NULL, m); 2384 l = 0; 2385 done = 1; 2386 break; 2387 } 2388 t = ((ipfw_insn_nat *)cmd)->nat; 2389 if (t == NULL) { 2390 nat_id = (cmd->arg1 == IP_FW_TABLEARG) ? 2391 tablearg : cmd->arg1; 2392 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2393 2394 if (t == NULL) { 2395 retval = IP_FW_DENY; 2396 l = 0; /* exit inner loop */ 2397 done = 1; /* exit outer loop */ 2398 break; 2399 } 2400 if (cmd->arg1 != IP_FW_TABLEARG) 2401 ((ipfw_insn_nat *)cmd)->nat = t; 2402 } 2403 retval = ipfw_nat_ptr(args, t, m); 2404 } 2405 l = 0; /* exit inner loop */ 2406 done = 1; /* exit outer loop */ 2407 break; 2408 2409 case O_REASS: { 2410 int ip_off; 2411 2412 f->pcnt++; 2413 f->bcnt += pktlen; 2414 l = 0; /* in any case exit inner loop */ 2415 ip_off = ntohs(ip->ip_off); 2416 2417 /* if not fragmented, go to next rule */ 2418 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 2419 break; 2420 2421 args->m = m = ip_reass(m); 2422 2423 /* 2424 * do IP header checksum fixup. 2425 */ 2426 if (m == NULL) { /* fragment got swallowed */ 2427 retval = IP_FW_DENY; 2428 } else { /* good, packet complete */ 2429 int hlen; 2430 2431 ip = mtod(m, struct ip *); 2432 hlen = ip->ip_hl << 2; 2433 ip->ip_sum = 0; 2434 if (hlen == sizeof(struct ip)) 2435 ip->ip_sum = in_cksum_hdr(ip); 2436 else 2437 ip->ip_sum = in_cksum(m, hlen); 2438 retval = IP_FW_REASS; 2439 set_match(args, f_pos, chain); 2440 } 2441 done = 1; /* exit outer loop */ 2442 break; 2443 } 2444 2445 default: 2446 panic("-- unknown opcode %d\n", cmd->opcode); 2447 } /* end of switch() on opcodes */ 2448 /* 2449 * if we get here with l=0, then match is irrelevant. 2450 */ 2451 2452 if (cmd->len & F_NOT) 2453 match = !match; 2454 2455 if (match) { 2456 if (cmd->len & F_OR) 2457 skip_or = 1; 2458 } else { 2459 if (!(cmd->len & F_OR)) /* not an OR block, */ 2460 break; /* try next rule */ 2461 } 2462 2463 } /* end of inner loop, scan opcodes */ 2464 #undef PULLUP_LEN 2465 2466 if (done) 2467 break; 2468 2469 /* next_rule:; */ /* try next rule */ 2470 2471 } /* end of outer for, scan rules */ 2472 2473 if (done) { 2474 struct ip_fw *rule = chain->map[f_pos]; 2475 /* Update statistics */ 2476 rule->pcnt++; 2477 rule->bcnt += pktlen; 2478 rule->timestamp = time_uptime; 2479 } else { 2480 retval = IP_FW_DENY; 2481 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 2482 } 2483 IPFW_RUNLOCK(chain); 2484 #ifdef __FreeBSD__ 2485 if (ucred_cache != NULL) 2486 crfree(ucred_cache); 2487 #endif 2488 return (retval); 2489 2490 pullup_failed: 2491 if (V_fw_verbose) 2492 printf("ipfw: pullup failed\n"); 2493 return (IP_FW_DENY); 2494 } 2495 2496 /* 2497 * Set maximum number of tables that can be used in given VNET ipfw instance. 2498 */ 2499 #ifdef SYSCTL_NODE 2500 static int 2501 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 2502 { 2503 int error; 2504 unsigned int ntables; 2505 2506 ntables = V_fw_tables_max; 2507 2508 error = sysctl_handle_int(oidp, &ntables, 0, req); 2509 /* Read operation or some error */ 2510 if ((error != 0) || (req->newptr == NULL)) 2511 return (error); 2512 2513 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 2514 } 2515 #endif 2516 /* 2517 * Module and VNET glue 2518 */ 2519 2520 /* 2521 * Stuff that must be initialised only on boot or module load 2522 */ 2523 static int 2524 ipfw_init(void) 2525 { 2526 int error = 0; 2527 2528 ipfw_dyn_attach(); 2529 /* 2530 * Only print out this stuff the first time around, 2531 * when called from the sysinit code. 2532 */ 2533 printf("ipfw2 " 2534 #ifdef INET6 2535 "(+ipv6) " 2536 #endif 2537 "initialized, divert %s, nat %s, " 2538 "default to %s, logging ", 2539 #ifdef IPDIVERT 2540 "enabled", 2541 #else 2542 "loadable", 2543 #endif 2544 #ifdef IPFIREWALL_NAT 2545 "enabled", 2546 #else 2547 "loadable", 2548 #endif 2549 default_to_accept ? "accept" : "deny"); 2550 2551 /* 2552 * Note: V_xxx variables can be accessed here but the vnet specific 2553 * initializer may not have been called yet for the VIMAGE case. 2554 * Tuneables will have been processed. We will print out values for 2555 * the default vnet. 2556 * XXX This should all be rationalized AFTER 8.0 2557 */ 2558 if (V_fw_verbose == 0) 2559 printf("disabled\n"); 2560 else if (V_verbose_limit == 0) 2561 printf("unlimited\n"); 2562 else 2563 printf("limited to %d packets/entry by default\n", 2564 V_verbose_limit); 2565 2566 /* Check user-supplied table count for validness */ 2567 if (default_fw_tables > IPFW_TABLES_MAX) 2568 default_fw_tables = IPFW_TABLES_MAX; 2569 2570 ipfw_log_bpf(1); /* init */ 2571 return (error); 2572 } 2573 2574 /* 2575 * Called for the removal of the last instance only on module unload. 2576 */ 2577 static void 2578 ipfw_destroy(void) 2579 { 2580 2581 ipfw_log_bpf(0); /* uninit */ 2582 ipfw_dyn_detach(); 2583 printf("IP firewall unloaded\n"); 2584 } 2585 2586 /* 2587 * Stuff that must be initialized for every instance 2588 * (including the first of course). 2589 */ 2590 static int 2591 vnet_ipfw_init(const void *unused) 2592 { 2593 int error; 2594 struct ip_fw *rule = NULL; 2595 struct ip_fw_chain *chain; 2596 2597 chain = &V_layer3_chain; 2598 2599 /* First set up some values that are compile time options */ 2600 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 2601 V_fw_deny_unknown_exthdrs = 1; 2602 #ifdef IPFIREWALL_VERBOSE 2603 V_fw_verbose = 1; 2604 #endif 2605 #ifdef IPFIREWALL_VERBOSE_LIMIT 2606 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 2607 #endif 2608 #ifdef IPFIREWALL_NAT 2609 LIST_INIT(&chain->nat); 2610 #endif 2611 2612 /* insert the default rule and create the initial map */ 2613 chain->n_rules = 1; 2614 chain->static_len = sizeof(struct ip_fw); 2615 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO); 2616 if (chain->map) 2617 rule = malloc(chain->static_len, M_IPFW, M_WAITOK | M_ZERO); 2618 2619 /* Set initial number of tables */ 2620 V_fw_tables_max = default_fw_tables; 2621 error = ipfw_init_tables(chain); 2622 if (error) { 2623 printf("ipfw2: setting up tables failed\n"); 2624 free(chain->map, M_IPFW); 2625 free(rule, M_IPFW); 2626 return (ENOSPC); 2627 } 2628 2629 /* fill and insert the default rule */ 2630 rule->act_ofs = 0; 2631 rule->rulenum = IPFW_DEFAULT_RULE; 2632 rule->cmd_len = 1; 2633 rule->set = RESVD_SET; 2634 rule->cmd[0].len = 1; 2635 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 2636 chain->rules = chain->default_rule = chain->map[0] = rule; 2637 chain->id = rule->id = 1; 2638 2639 IPFW_LOCK_INIT(chain); 2640 ipfw_dyn_init(); 2641 2642 /* First set up some values that are compile time options */ 2643 V_ipfw_vnet_ready = 1; /* Open for business */ 2644 2645 /* 2646 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 2647 * Even if the latter two fail we still keep the module alive 2648 * because the sockopt and layer2 paths are still useful. 2649 * ipfw[6]_hook return 0 on success, ENOENT on failure, 2650 * so we can ignore the exact return value and just set a flag. 2651 * 2652 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 2653 * changes in the underlying (per-vnet) variables trigger 2654 * immediate hook()/unhook() calls. 2655 * In layer2 we have the same behaviour, except that V_ether_ipfw 2656 * is checked on each packet because there are no pfil hooks. 2657 */ 2658 V_ip_fw_ctl_ptr = ipfw_ctl; 2659 error = ipfw_attach_hooks(1); 2660 return (error); 2661 } 2662 2663 /* 2664 * Called for the removal of each instance. 2665 */ 2666 static int 2667 vnet_ipfw_uninit(const void *unused) 2668 { 2669 struct ip_fw *reap, *rule; 2670 struct ip_fw_chain *chain = &V_layer3_chain; 2671 int i; 2672 2673 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 2674 /* 2675 * disconnect from ipv4, ipv6, layer2 and sockopt. 2676 * Then grab, release and grab again the WLOCK so we make 2677 * sure the update is propagated and nobody will be in. 2678 */ 2679 (void)ipfw_attach_hooks(0 /* detach */); 2680 V_ip_fw_ctl_ptr = NULL; 2681 IPFW_UH_WLOCK(chain); 2682 IPFW_UH_WUNLOCK(chain); 2683 IPFW_UH_WLOCK(chain); 2684 2685 IPFW_WLOCK(chain); 2686 ipfw_dyn_uninit(0); /* run the callout_drain */ 2687 IPFW_WUNLOCK(chain); 2688 2689 ipfw_destroy_tables(chain); 2690 reap = NULL; 2691 IPFW_WLOCK(chain); 2692 for (i = 0; i < chain->n_rules; i++) { 2693 rule = chain->map[i]; 2694 rule->x_next = reap; 2695 reap = rule; 2696 } 2697 if (chain->map) 2698 free(chain->map, M_IPFW); 2699 IPFW_WUNLOCK(chain); 2700 IPFW_UH_WUNLOCK(chain); 2701 if (reap != NULL) 2702 ipfw_reap_rules(reap); 2703 IPFW_LOCK_DESTROY(chain); 2704 ipfw_dyn_uninit(1); /* free the remaining parts */ 2705 return 0; 2706 } 2707 2708 /* 2709 * Module event handler. 2710 * In general we have the choice of handling most of these events by the 2711 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 2712 * use the SYSINIT handlers as they are more capable of expressing the 2713 * flow of control during module and vnet operations, so this is just 2714 * a skeleton. Note there is no SYSINIT equivalent of the module 2715 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 2716 */ 2717 static int 2718 ipfw_modevent(module_t mod, int type, void *unused) 2719 { 2720 int err = 0; 2721 2722 switch (type) { 2723 case MOD_LOAD: 2724 /* Called once at module load or 2725 * system boot if compiled in. */ 2726 break; 2727 case MOD_QUIESCE: 2728 /* Called before unload. May veto unloading. */ 2729 break; 2730 case MOD_UNLOAD: 2731 /* Called during unload. */ 2732 break; 2733 case MOD_SHUTDOWN: 2734 /* Called during system shutdown. */ 2735 break; 2736 default: 2737 err = EOPNOTSUPP; 2738 break; 2739 } 2740 return err; 2741 } 2742 2743 static moduledata_t ipfwmod = { 2744 "ipfw", 2745 ipfw_modevent, 2746 0 2747 }; 2748 2749 /* Define startup order. */ 2750 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN 2751 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 2752 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 2753 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 2754 2755 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 2756 MODULE_VERSION(ipfw, 2); 2757 /* should declare some dependencies here */ 2758 2759 /* 2760 * Starting up. Done in order after ipfwmod() has been called. 2761 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 2762 */ 2763 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2764 ipfw_init, NULL); 2765 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2766 vnet_ipfw_init, NULL); 2767 2768 /* 2769 * Closing up shop. These are done in REVERSE ORDER, but still 2770 * after ipfwmod() has been called. Not called on reboot. 2771 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 2772 * or when the module is unloaded. 2773 */ 2774 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2775 ipfw_destroy, NULL); 2776 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2777 vnet_ipfw_uninit, NULL); 2778 /* end of file */ 2779